Add resume-command output to dispatch search

[jongio]

dispatch search --ids | dispatch open --stdin --print can produce resume commands, but it takes a pipeline and hides the command output behind a second command. Pickers and aliases are simpler when search can print executable resume commands directly.

Acceptance criteria:

• dispatch search --commands prints one resume command per matching session.
• dispatch search --format commands is accepted.
• The command uses the same config-aware resume command builder as dispatch open --print.
• The help text lists the new format.